The present invention relates to a spinning machine for forming a metallic material by use of a forming roller while the roller is being rotated.
A prior art spinning machine is shown in FIG. 10, which comprises a spindle 5, a mold 1 fixedly mounted on the spindle 5, a tailstock spindle 2 and a forming roller 6 rotatably mounted on one end of an arm 7. A disk-shaped metallic material 3 is mounted between the mold 1 and the tailstock spindle 2.
The arm 7 is reciprocably mounted on a reciprocating carriage 8 which is driven by a hydraulic cylinder 9 so as to reciprocate along a guide frame 10 in a direction perpendicular to a direction of back-and-forth movement of the arm 7.
On the guide frame 10 is fixedly mounted a gauge 11 on which is mounted another gauge 12 so as to be pivotable about a shaft 13 by means of a hydraulic cylinder 14.
On the rear end of the arm 7, there is provided a servo valve 15 having its working piece 16 in engagement with the gauges 11 and 12. The hydraulic cylinder for the arm 7 is controlled by the servo valve 15 so that the forming roller 6 can move following the contour of the gauges 11 and 12.
With this prior art machine, the hydraulic cylinders 9 and 14 are controlled with an electrical program so that the pivotable gauge 12 will pivot in the direction of the arrow by a predetermined angle per stroke of the reciprocating carriage 8 to gradually bend the material in the initial stage toward the mold 1 as shown by chain lines, and then to press the material 3 against the mold 1.
Since the forming roller 6 is adapted to move following the contour of the gauges, it is necessary to prepare gauges 11 and 12 having different contours for a mold 1 of different shapes.
Further, since it is difficult to specify the directional properties and elongation of the metallic plate to be formed, a long time is required for the setting of the mold 1 and the gauges 11 and 12.